The present disclosure relates to an instrument that may be used for Hair Restoration Surgery (HRS) or any subdermal tissue removal procedure without altering the integrity of the overlying skin surface. The surgical method of donor follicle removal in HRS is based on the principal of “donor dominance”, wherein the region of the scalp in which the hair is destined to persist throughout a person's lifetime, known as the “donor area” will continue to grow in the same fashion, when transplanted to the “recipient area”, or the scalp zone of non-permanent hair growth.
Original HRS techniques included the excision of large punch grafts from the donor area and transplantation to the recipient area. Utilization of these large grafts was necessary in order to ensure hair survival after transplantation. Smaller grafts, or implantation into smaller recipient sites, were often not feasible due to the low graft viability secondary to decreased blood perfusion of transplanted grafts. While this large-graft method enabled transplanted graft growth within the recipient area, the grafts often had an unnatural, “pluggy” appearance, and the punched-out scars in the donor area left an unattractive buckshot-type pattern in the back of a patient's head.
To overcome these methodical and aesthetic shortcomings of many original HRS techniques, an alternative method for donor hair harvesting was proposed: the strip harvest technique. This alternative approach involved the following procedural steps: removing a strip of hair-follicle bearing skin from the donor region, suturing the donor wound closed, dissecting out each individual follicle or cluster of follicles (a.k.a. a “follicular unit”, FU), and transplanting each individual FU separately in the recipient area. Each FU may contain one or more individual hair follicles and can be defined based on the naturally-occurring arrangement of a bulb region. An FU may be classified based on its caliber and the quantity of hairs it contains as a single-haired FU, a fine-single-haired FU, a double-haired FU, a fine double-haired FU, a triple-haired FU, or a follicular family containing four or more intact hair follicles.
The approach, known as “micrografting” or “follicular unit transplanting” (FUT), helped to create a more natural and less “pluggy” appearance in the recipient area than that resulting from the large grafts. Furthermore, this new approach left only a linear scar in the donor area, rather than a more obvious buckshot pattern.
In order to achieve a maximum number of grafts via the “micrografting” technique, many patients requested wider donor strip removal which would, in turn, yield more donor hair follicles. A consequence of this more aggressive approach is that patients are increasingly left with relatively large (2-10 mm) and obvious linear scars in the donor portion of their head. To reduce or eliminate this aesthetically displeasing result, a process known as Follicular Unit Extraction (FUE) was developed. In FUE, each individual follicular unit is meticulously punched out from the donor area with a small biopsy punch, and then transplanted into the recipient area. This differs from the original approach to HRS in that FUE involves the transfer of only individual FU's, rather than large (4-5 mm) punch grafts.
However, several disadvantages persisted with the advent of FUE: a high percentage (up to 40%) of hairs are transected (thus, limiting their survival), a moth-eaten scarring pattern often still remains (though to a lesser degree than seen with the original, larger punch grafts) from where FUs are extracted, and a considerable number of patients (up to 30%) are not candidates for FUE based on their hair characteristics (e.g. light color or considerable and unpredictable curl beneath the skin surface) that present undue challenges for the surgeon.
The technique described herein allows for: 1) the isolation of an intact hair follicle with maximal tissue (both dermal and subcutaneous) surrounding the stem cell-containing portion of the follicle without traumatizing the overlying skin surface; and 2) eliminates the stigma of any apparent scar in the donor area from which the hair is harvested.
A challenge associated with extracting/harvesting tissue that includes essential portions beneath the skin surface often pertains to determination of the location, depth, and position of the desired tissue. Without cutting or altering the integrity of the overlying skin surface, obtaining the desired tissue segment beneath the skin is especially difficult. In order to overcome these challenges, a device is disclosed herein to enable a user to 1) manipulate a visualization device located outside of the skin surface to identify a target tissue, and 2) harvest tissue located beneath the skin surface based on the information provided by the visualization device. Movement of the visualization device and the internal issue extraction device are directly tied to the movements of the operator performing each movement outside of the skin surface.
Without cutting or altering the overlying skin surface, the design described herein enables a precisely-controlled extraction/harvest of desired tissue that accounts for the borders of the desired tissue, the angle and direction of the tissue (e.g. hair follicle) as it is positioned beneath the skin surface, and the depth of penetration of the desired tissue all while effectively avoiding inclusion of undesirable surrounding tissue in the harvest or injuring vital vessels or nerve plexes in the process.
The direct association between the visualization/manipulation of a probe located outside of the body and the extraction/harvesting module located within the body that approaches, but does not directly touch, the outerlying probe enables this unique achievement.